Thick culm (ND) ND0025 ND0145 ND0236 ND0401 ND0614 ND0656 ND0807 ND1103 ND1108 ND1131 ND1256 ND1310 ND1517 ND1555 ND1604 ND1629 ND1648 ND1706 ND1711 ND1905 ND1915 ND1965 ND2022 ND2054